Black tea natural dye is usually recognised to contain functional colouring matters, which has long been used for the coloration of textile materials. However, due to poor binding and colour fastness, a large number of mordants have been used in the dyeing process, leading to serious environmental problems. To address these issues, we have developed a no-mordant pad-dry dyeing strategy for dyeing flax fabrics with functional components of Keemun black tea (KBT) waste. The dyed flax fabrics showed outstanding colour fastness to perspiration, rubbing, and washing. Moreover, increasing the KBT extract concentration, dyeing time, and temperature, and decreasing the pH level could significantly enhance the K/S values. Fourier-transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) results revealed that theaflavin compounds dyed thoroughly the fibres successfully through hydrogen bonding force, and the theaflavin compounds could be bound to fibres stably through van der Waals and hydrogen bonding forces based on Independent Gradient Model (IGM) calculations. In addition, the dyed flax fabrics possessed good ultraviolet (UV) protection and antibacterial performance. This work proposes novel approaches for the reuse of KBT waste and the simultaneous coloration and functionalisation of flax fabric.

中文翻译：

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祁门红茶废料功能性提取物的高结合牢度染料用于亚麻织物染色

红茶天然染料通常被认为含有功能性色素，长期以来一直用于纺织材料的着色。但由于结合力和色牢度差，染色过程中大量使用媒染剂，导致严重的环境问题。为了解决这些问题，我们开发了一种非媒染轧干染色策略，用于用祁门红茶 (KBT) 废料的功能成分对亚麻织物进行染色。染色的亚麻织物表现出出色的耐汗渍、摩擦和洗涤色牢度。此外，增加 KBT 提取物浓度、染色时间和温度，以及降低 pH 水平可以显着提高K / S价值观。傅里叶变换红外（FTIR）光谱和X射线光电子能谱（XPS）结果表明，茶黄素类化合物通过氢键成功地彻底染色纤维，并且茶黄素类化合物可以通过范德华力和氢键与纤维稳定结合基于独立梯度模型 (IGM) 计算。此外，染色亚麻织物具有良好的紫外线防护和抗菌性能。这项工作提出了重新利用 KBT 废物以及同时对亚麻织物进行着色和功能化的新方法。